1. Field of the Invention
The present invention relates to fluid filters, and more particularly to liquid filters having cleanable screens.
2. Description of the Related Art
Many different kinds of fluid filters have been developed over the years. They are available in a wide variety of sizes and shapes. The filtering media are also widely variable to suit the particular fluid to be filtered.
A particularly important type of filter is used with swimming pools. The filters are necessary to keep the water clean from such contaminants as grass, leaves, plastic, and paper.
In recent years, relatively small portable swimming pools have become increasing popular. Such pools are sometimes referred to as soft side pools, and they are marketed under trademarks such as Sand And Sun and Easy Set. Soft side pools are larger than traditional children's wading pools, but they are smaller than full size above-ground or in-ground pools. In some cases, soft side pools are quite large; one commercially available model is 18 feet long and four feet wide. Some soft side pools are inflatable using air pressure. Other models use the pool water to stabilize the pool in place.
The soft side pool invariably includes a pump system that continuously circulates water in the pool. Water is drawn out of the pool and then looped back into the pool through the pump system.
Like the larger above-ground and in-ground pools, soft side pools must be kept clean in order to assure maximum enjoyment by their users. Consequently, it is a common practice to include a water filter in the pump system. The filter traps solid debris from the water and permits only filtered water to circulate back to the pool. Eventually the filter becomes clogged.
In the past, the filters of soft side pool pump systems were disposable. That is, when the filters became clogged, they were discarded and replaced with a new filter. Depending on the amount of pool usage, a filter lasted between approximately one and two weeks. Consequently, it was a costly matter to keep the pools clean. Further, the discarded filters eventually ended up in landfills, which was undesirable from an environmental standpoint.
Thus, a need exists for improvements in filters for soft side pools.